Heise: Chloride of Lime 



25 



The interaction of chloride of lime and organic matter as 

 affected by concentration. — If the interaction of chloride of lime 

 with organic matter is a monomolecular reaction, it follows di- 

 rectly that the percentage of chloride of lime decomposed should 

 be independent of the initial concentration. In other words, the 

 amount of chlorine consumed in a given time should be a con- 

 stant fraction of the quantity added. For example, (5) when 

 the addition of available chlorine to sewage is doubled, the amount 

 of chlorine absorbed will also be doubled, within certain limits, 

 a fact which has an important bearing on the economical appli- 

 cation of hypochlorites for disinfecting purposes. 



A good illustration of this regularity is shown in the following 

 series of determinations on the interaction of chloride of lime 

 and urea. Different quantities of filtered chloride of lime solu- 

 tion, varying in strength from 2 to about 100 milligrams of 

 available chlorine, were diluted to 100 cubic centimeters, placed 

 in glass-stoppered bottles, and digested twenty-one hours in the 

 dark at 28° C. with 2 cubic centimeters of 0.01 molar urea solu- 

 tion. At the end of the digestion period the samples were anal- 

 yzed, with the results listed in Table IV. 



Table IV. — Interaction of varying concentrations of calcium hypochlorite 

 with urea. 



Hypochlorite add- 

 ed as— 



Available chlorine 

 consumed. 



Solution. 



Available 

 chlorine. 



Ob- 

 served. 



Calcu- 

 lated, a 



1 



cc. 



mg. 



mg. 



1 

 mg. 



1.0 



2.3 



2.1 



2.2 



1.5 



3.4 



3.1 



3.3 



2.0 



4.6 



4.3 



4.4 



3.0 



6.9 



6.5 



6.6 



4.0 



9.2 



8.8 



8.9 



5.0 



11.5 



11.0 



11.1 



6.0 



13.8 



13.3 



13.3 



7.0 



15.3 



14.9 



15.5 



8.0 



18.3 



17.7 



17.7 



9.0 



20.6 



20.0 



20.0 



10 



22.9 



22.2 



22.2 



15 



34.4 



33.5 33.3 



20 



45.8 



44.5 44.4 



25 57. 2 



55.6 55.5 



30 68. 7 



67.0 ' 66.6 



40 91. 6 



88.7 | 88.8 i 



From the values obtained with 6, 8, 9, and 10 cubic centimeters of solution. 



